The present invention relates to the field of electrical connectors for electronic equipment. Specifically, the present invention relates to modular jack connectors with an integrated magnetic module.
There is an escalating need for computer networking hardware that can support the high frequencies associated with multi-gigabit speeds. Circuit board designers face a number of high-frequency related design challenges including high susceptibility of signal loss or distortion due to electromagnetic noise and jitter. Design and placement of countermeasures such as isolation of problem components, signal filtering, and EMI shielding requires extreme care. This attention to detail applies not only to each self-contained item of hardware, but also to the cables and connectors that tie these devices to the outside world. Often, it is these linking elements that are the Achilles heel of the system.
In addition to signal integrity issues, market demand requires that nearly all electronic hardware components must be designed with product size reduction as a goal. The trend towards smaller, more highly optimized communications devices has spurred a concurrent trend to integrate multiple system components within a single housing. The integration of magnetic interface components into standard modular jack connectors is one manifestation of this trend.
Moving the magnetic components from the circuit board into the connector improves reliability, reduces electromagnetic noise, and provides size reduction and design simplification benefits to the printed circuit board. Reliability of the magnetics is improved due to the reduction of heat exposure during assembly. Noise is reduced by isolating and shielding the magnetics from the long traces and problem components of the circuit board. Simplification of design and reduction of the overall size of the printed circuit board are achieved because one connector can take the place of many components. Use of an integrated connector thus improves performance and reliability, promotes miniaturization and reduces manufacturing costs by streamlining manufacturing.
In prior art integrated connectors, for instance U.S. Pat. No. 5,069,641, the magnetic components as well as other components such as termination resistors are assembled onto a small printed circuit board that fits within the connector housing. Plated through-holes at opposite ends of the printed circuit board accept sets of pins that will connect to the hardware and the cable. To assemble the connector, pins are pre-attached to the circuit board through the holes at one end, the attached pins are slipped through holes in the housing as the circuit board is slipped into its molded slot in the housing, and then the second set of pins are inserted into the plated through-holes at the opposite end of the circuit board. The housing has a molded set of grooves that holds the second set of pins in an array in which they are electrically isolated from one another. This subassemblyxe2x80x94housing, printed circuit board, and two sets of pinsxe2x80x94is then assembled into the modular jack body, thus protecting the circuit board and its sensitive components.
Although prior art integrated connectors provide a number of benefits over modular jacks without integrated components, the sensitive components can easily be damaged by handling or heat exposure during the multiple assembly steps. An improved design requiring fewer assembly steps would, therefore, be of significant benefit.
It is, therefore, an object of the present invention to provide integrated connector assemblies that have the following improvements over prior art integrated connectors:
(a) require fewer assembly operations,
(b) have reduced thermal exposure to the magnetic components, and
(c) have a higher manufacturing yield.
These and other objects of the invention will become apparent upon review of the specification and appended claims.
In accordance with the present invention, the circuit for the integrated components is printed directly on the housing for the connector, rather than fabricated as a separate circuit board. The circuit is formed from a metal-filled polymer paste that is thermally processed at or below typical solder reflow temperatures to form an electrical conductor. The paste is deposited using any one of a number of methods, such as screen-printing or needle dispensing, commonly known to those of skill in the art. The components to be integrated may then be attached directly to the circuit, or in an alternative embodiment, may be placed into the unprocessed conductive paste to achieve component attachment and circuit formation in a single step. Likewise, the pins may be attached to the circuit after the conductive paste has been cured or may be placed into the wet paste for concurrent pin-attachment and conductive paste curing.
The present invention thus provides novel electrical connectors and methodology which allows one to substantially reduce the number of assembly steps required for the manufacture of integrated connectors. Because the circuit is directly integrated with the connector housing, the order in which the pins and components are attached to the circuit can be manipulated to provide an optimum manufacturing flow that minimizes potential damage to the components. The potential to complete all assembly steps without ever exposing the magnetic components to solder reflow temperatures can substantially improve the reliability and performance of these sensitive components. In addition, the points of attachment of the pins to the circuit may be encased in potting compound along with the integrated components thus providing the connector with improved mechanical ruggedness and resistance to adverse environmental conditions.